Currently, various metrics are used to describe properties of muscular activation and function. Often, the measurement of muscle activation and function is measured by surface electromyography (sEMG), and analysis of the sEMG can include the following: the instantaneous root mean square amplitude (RMS), the average rectified amplitude, and the mean/median power frequency. The latter category can be referred to as an index of muscle fatigue. However, these currently available metrics are limited in ability to adequately characterize muscular activation. Additionally, these metrics are geared towards researchers and professionals for use in medical diagnoses. Certain qualities/quantities of muscle activation that are significant to athletic or average consumers have not yet been developed, and there is currently a lack of protocols to automatically generate these metrics.
The sEMG assessments can be sorted into three general groups of muscle activity: static muscle activity, dynamic muscle activity, or combination of static and dynamic muscle activities. The different muscle activity paradigms can be useful for different muscle assessments.
A static muscle activity may occur with no load (i.e. sitting) or with an isometric load (no movement of limb). Static muscle activity evaluation can include observation of the rectified amplitude of the sEMG data. The static muscle activity evaluation can be useful for a specific muscle or muscle group or as a comparison to other muscles or muscle groups. Absolute levels of the sEMG data can be monitored through the RMS of the sEMG amplitude (e.g., RMS of sEMG amplitude), and abnormally large values of the RMS sEMG can be identified or determined. Rhythmic contraction patterns of the muscle or muscle groups can be identified or determined, and may also be based on rectified amplitude. During an isometric loading protocol, a subject can exert an amount of force while keeping the limb fixed in a single position. Usually, the force exerted is measured as a fixed percentage of Maximum Voluntary Contraction (MVC). Then, the median frequency (MF) or mean power frequency (MPF) can be measured or determined by observing or analyzing the frequency spectrum of the sEMG. In this manner, the fatigue level of the muscles can be established, and the point at which fatigue begins to occur may be identified.
Dynamic muscle activity evaluations can ascertain relationships between sEMG amplitude and force, which have been shown to be “curvilinear”, or non-linear at the extremes of the force range (e.g., very little force, or a lot of force) and essentially linear for the majority of the force/amplitude relationship. Evaluating that relationship is useful for dynamic muscle activity sEMG evaluation. Methods for implementing dynamic muscle activity evaluations can include incrementally increasing the force exerted by the muscle by way of a machine that measures force, and measuring the sEMG amplitude of the muscle activity that is associated with various force levels. Dynamic muscle activity evaluations can be used in the evaluation of torque and paralysis. There are dynamic muscle activity evaluation methods for: muscle imbalance, trigger points, cocontractions, and fasciculations.
However, the abovementioned muscle assessment methods can be used to assess a variety of pathologies and physiological states which may correspond to, or attempt to correspond to, clinical and/or medical conditions. These methods have typically been designed to be performed by specialists (e.g., MD, chiropractor, physical therapist, etc.). These muscle assessment methods are usually restricted to controlled settings in the presence of these specialists. Thus, there is not a way for a common person to implement muscular assessment on their own. Therefore, there remains a need to bring the ability to implement muscle assessment to the masses.
These figures are arranged in accordance with at least one of the embodiments described herein, and which arrangement may be modified in accordance with the disclosure provided herein by one of ordinary skill in the art.